# Can we determine the densities of different materils?

Essay by padishah5_777 August 2007

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30th AugustSabina AbayevaDensity Labhttp://home.att.net/~cat4a/images/archimedes2.jpgAim:Density is mass per unit of volume. Different materials have different densities. In our lab our main aim is to determine the densities of different solids and liquids.

Materials and equipment:A brass cylinderA copper cylinderAn iron cylinderA hydrometerRuler (30cm)Canola oilWaterBalance (scales)CalculatorCylindersObservations:We found mass by putting our metals and liquids onto the balance. When we found out the mass we moved onto the volume, this time is was a two step process. We used the volume formula for cylinders since all of our materials had this shape:ÃÂ X r ÃÂ² X hAfter calculating the volume using the formula we calculated it again but this time using the water displacement method. After finding the volume and mass we could find the density. We calculated the density also two times, each time changing the result and substituting the 'volume calculated' by 'water displacement'.

After that we moved onto the experimental error which was also very important.

We found out how close or far we were to the actual numbers by sing this formula:Our value ÃÂ actual value / actual value * 100The results are shown in the table below:Experimental error(%)Density (g/cc) by water displacementDensity (g/cc) calculatedVolume (cc) by water displacementVolume (cc) calculatedMass (g)MaterialXXHydrometer 1X50 cc50gWater-1.3%X0.898X50cc45gCanola oil13%9.510.06cc5.65457.03gCopper12%8.58.896cc5.65450.25gIron10%9.69.726cc5.65454.95gBrassConclusion:Density is mass per unit of water. We can use two methods to calculate the densities of solids and liquids. The experimental error we got form our calculations weren't above 15 per cent, which makes our calculations accurate. In order for a liquid or solid to float on water it needs to be less than the density of water. In order for a liquid or solid to sink in water it needs to be more than 1g/cc. The density doesnÃÂt depend on the amount of the material it is always a ratio of...